Mechanical photovoltaic module cartridge and method of construction

ABSTRACT

A photovoltaic panel cartridge for mounting a plurality of photovoltaic panels and method of its construction are described. The photovoltaic panel cartridge is formed from a unitary frame with internal beams and struts for stability. The photovoltaic panels are inserted into channels within the frame, struts, and/or the internal beams in order to be mounted to the photovoltaic panel cartridge and secured to mounting regions on a different one of the frame, struts, and/or internal beams. The photovoltaic panel cartridge is configured to be stacked upon similarly configured photovoltaic panel cartridges for ease in transport and to reduce damage to the photovoltaic panels during transport. The photovoltaic panel cartridge may be slidably mounted to rails of a support structure.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 12/957,808, filed Dec. 1, 2010, which in turn is a continuation-in-part of U.S. patent application Ser. No. 12/846,621, filed Jul. 29, 2010, Ser. No. 12/846,644, filed Jul. 29, 2010, and Ser. No. 12/846,686, filed Jul. 29, 2010, the disclosures of each of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

Embodiments of the invention relate to the field of photovoltaic (PV) power generation systems, and more particularly to a system for simplifying installation of photovoltaic panels, also known as PV modules, in large-scale arrays.

BACKGROUND OF THE INVENTION

Photovoltaic power generation systems are currently constructed by installing a foundation system (typically a series of posts or footings), a module structural support frame (typically brackets, tables or rails, and clips), and then mounting individual photovoltaic panels to the support frame. The photovoltaic panels are then grouped electrically together into PV strings, which are fed to an electric harness. The harness conveys electric power generated by the photovoltaic panels to an aggregation point and onward to electrical inverters.

Prior art commercial scale PV systems such as this must be installed by moving equipment, materials, and labor along array rows to mount photovoltaic panels on the support frames one-at-a-time. This is a time-consuming process, which becomes increasingly inefficient with larger scale systems.

With innovations in PV cell efficiency quickly making PV-generated energy more cost-effective, demand for large-scale PV systems installations is growing. Such systems may have a row length of half a mile or more. Accordingly, a simplified system for photovoltaic panel installation is needed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a cartridge for mounting a plurality of photovoltaic panels in a first embodiment.

FIG. 2 is a close-up perspective view showing a recessed area in the cartridge.

FIGS. 3A-3B are close-up perspective views showing photovoltaic panels mounted in the cartridge.

FIG. 3C is a cross-sectional side view showing a photovoltaic panel mounted in the cartridge.

FIG. 4 is a top-down view showing a schematic of the electrical wiring in the cartridge

FIG. 5 is a perspective view showing attachment structures on the underside of the cartridge.

FIGS. 6A-6B are perspective views, respectively showing different arrangements for mounting the cartridge to spaced parallel support rails.

FIG. 7 is a cross-sectional side view showing one embodiment of an attachment structure for mounting the cartridge to a support rail.

FIG. 8 is a perspective view showing another embodiment of an attachment structure for mounting the cartridge to a support rail.

FIG. 9 is a cross-sectional side view showing another embodiment of an attachment structure for mounting the cartridge to a support rail.

FIG. 10A is a top-down view showing another embodiment of the cartridge.

FIGS. 10B-C are a side view and cross-sectional side view of the cartridge along axes A and B, as shown in FIG. 10A.

FIG. 11 is a perspective view showing another embodiment of an attachment structure for mounting a cartridge to parallel support rails.

FIG. 12 is a side view showing the attachment structure of FIG. 11 for mounting a cartridge to parallel support rails provided on a folding table.

FIG. 13 is a close-up cross-sectional side view of the attachment structure of FIG. 11.

FIG. 14 is a perspective view of another embodiment of a cartridge.

FIG. 15 is a top view of a cartridge according to another embodiment of a cartridge.

FIG. 16A is a cross sectional view of a cartridge frame employed in the FIG. 15 embodiment.

FIG. 16B is a cross sectional view of a strut employed in the FIG. 15 embodiment.

FIG. 16C is a cross sectional view of a strut according to a second embodiment.

FIG. 16D is a cross sectional view of a central beam employed in the FIG. 15 embodiment.

FIG. 16E is a cross sectional view of a cartridge frame according to another embodiment.

FIG. 16F is a cross sectional view of a strut according to a third embodiment.

FIG. 16G is a cross sectional view of a central beam according to another embodiment.

FIGS. 17A-D illustrate the process of installation of photovoltaic panels into a cartridge depicted in FIG. 15.

FIG. 17E illustrates the process of installation of photovoltaic panels into a cartridge using the frame, struts, and central beam depicted in FIGS. 16E-G.

FIG. 18 is a bottom view of the FIG. 15 embodiment.

FIGS. 19A-F illustrate the process of formation of a cartridge frame.

FIG. 20 is a top perspective view of a partially completed cartridge.

FIG. 21A is a top perspective view of a stack of completed cartridges.

FIG. 21B is a cut-away top perspective view of stacked cartridges.

FIG. 21C is a top perspective view of a partially loaded shipping container containing stacks of completed cartridges.

FIGS. 22A-D are perspective views of cartridges being mounted to support rails one after another.

FIG. 23 is a perspective view showing a cartridge for mounting a single photovoltaic panel.

FIGS. 24A-B show perspective views of FIG. 23 cartridges being mounted to support rails on a roof structure one after another.

FIG. 25 is a view showing operation of a robotic installation system for installing FIG. 1 cartridges.

FIGS. 26A-E are views showing operation of a push actuator of the FIG. 25 robotic installation system.

FIG. 27A is a perspective showing the installation of a cartridge of FIG. 15 to cartridge mounting rails.

FIG. 27B is a perspective view showing a cartridge of FIG. 15 being slid along cartridge mounting rails.

FIG. 27C is a perspective view showing a cartridge of FIG. 15 being slid along cartridge mounting rails according to a second embodiment.

FIG. 27D is a perspective view showing a cartridge of FIG. 17E being slid along cartridge mounting rails.

FIG. 28A is a side view of the FIG. 15 embodiment mounted to cartridge mounting rails.

FIG. 28B is a side view of the FIG. 17E embodiment mounted to cartridge mounting rails.

FIGS. 29A-B are perspective views showing a field array installation using cartridges and support structures detailed herein.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and which illustrate specific embodiments of the invention. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to make and use them. It is also understood that structural, logical, or procedural changes may be made to the specific embodiments disclosed herein.

Described herein is a method for mounting and sliding a multiplicity of mountable photovoltaic panels along a rail system using a photovoltaic panel cartridge. For utility scale ground mounted photovoltaic systems or commercial or residential rooftop systems, the use of a rail system to slide cartridges each containing one or more photovoltaic panels into place provides several benefits. By moving all work to one or more locations along each row, e.g., at the head, the system maximizes the use of preassembled components, minimizes material movement logistics, and reduces both on-site field labor and equipment movement over the site. One embodiment of the system is constructed by installing a support structure comprising a plurality of spaced parallel rails, which may be ground or structure supported, designed to receive and allow sliding movement of a pre-assembled cartridge that supports either a single photovoltaic panel or a plurality of photovoltaic panels as a unit. The support structure could also comprise a photovoltaic tracking system which would allow the rails to be rotated.

A first embodiment of a cartridge 100 is depicted in FIGS. 1, 2, 3, 4 and 5. Cartridge 100 is a lightweight, cartridge-like structure that provides structural support and contains and supports a plurality of photovoltaic panels 120 a-h in a 4×2 array and facilitates their electrical interconnection. The cartridge 100 is made of either synthetic or natural structural material, including, but not limited to, aluminum, rolled steel, or other metals and plastics. As an alternative, and as shown by element 1400 in FIG. 14, the cartridge 1400 can be constructed in a honeycombed or gridded structure. This saves weight while maintaining structural strength.

As shown in more detail in FIGS. 1, 2 and 3A-3B, a plurality of photovoltaic panels 120 a-h are mounted in respective recessed areas 110 a-h of cartridge 100, with one such recessed area 110 f being shown without an installed photovoltaic panel in FIG. 2. Photovoltaic panels 120 a-h are held in place by being snapped, clipped, or otherwise securely seated in each of the recessed areas 110 a-h. The photovoltaic panels 120 a-h are preferably mounted in the recesses 110 a-h before conveyance of a cartridge to an installation site, so all that needs to be done at the installation site is to mount the cartridge 100 containing a plurality of photovoltaic panels to a support structure. Although an array of eight photovoltaic panels 120 a-h in a 4×2 array is shown in the figures as being supported by cartridge 100, it is understood that any number or arrangement of photovoltaic panels could be mounted on and supported by a cartridge 100. For instance, FIG. 24 shows a 4×1 array of photovoltaic panels on a cartridge 2200, while FIG. 25 shows a single photovoltaic panel on a cartridge 2300.

FIGS. 2 and 3A show one embodiment of an arrangement for mounting photovoltaic panels in the recessed areas 110 a-h of cartridge 100. One edge of a photovoltaic panel, e.g., 210 f (not shown) is slid under a lip groove 204 within recessed area 110 f and lowered into position. To secure a photovoltaic panel in place, clips 302 a-b which engage with an opposite edge of a photovoltaic panel are themselves engaged by screws or other fasteners with openings 202 a-b provided on a side of the recess 110 f opposite the side containing lip groove 204. Together with lip groove 204, clips 302 a and 302 b hold a photovoltaic panel in place within a recess. An alternate embodiment for securing the photovoltaic panels in the recesses is shown in FIG. 3B, which uses spring-back clips 312 a-b that overhang an edge of the recess. As one edge of a photovoltaic panel is slid under a lip groove 204 in a recess, it is then lowered into position, causing the opposite edge to press against the spring-back clips 312 a-b, which push back and bend until the photovoltaic panel clears the bottom of the clips. Once clear, the clips 312 a-b will slide back over top of the photovoltaic panel, securing it in place.

Clips and grooves are not the only way photovoltaic panels can be mounted in recesses of the cartridge 100; glue, Velcro™, or other known engagement means can be used. In another embodiment for securing the photovoltaic panels to the recesses, resilient engagement members can be used to hold the panels in place. FIG. 3C, for instance, shows a pair of rubber stoppers 322 a-b at opposite ends of a recessed area 110 f which allow panel 210 f to be slid under one of the stoppers 322 a and then pressed down past the other stopper 322 b to be held in place. The cartridge 100 is preferably configured so that whichever structure are used to hold a photovoltaic panel within a recess is used, photovoltaic panels 120 a-h are either flush with or below a top surface 210 of the cartridge 100. This allows the cartridge 100 to be stacked with like cartridges for shipping and also protects the photovoltaic panels 120 a-h while in storage or transit to an installation site.

In general, solar-generated electricity is harvested and transmitted through a pre-wired common bus or cable system integral to the cartridge 100. Some examples of a common bus system that may be employed are described in more detail in co-pending application Ser. No. 12/846,671, the disclosure of which is incorporated by reference herein. One embodiment of pre-wiring a cartridge 100 for connection to a common bus system 280 is schematically shown in FIGS. 2 and 4. As shown in FIG. 2, an electrical connector 206 can be provided in the lower surface of the recessed area 110 f so that when a photovoltaic panel is placed in a recessed area 110 f, a plug on the bottom of a photovoltaic panel engages electrical connector 206 to connect it to the common bus system 280. FIG. 2 also shows an electrical connector 208 provided in a sidewall of the recess 110 f that could be used in lieu of connector 206 to connect wiring 212 to side electrical connectors on a photovoltaic panel. An exemplary electrical connection schematic for a cartridge 100 is shown in FIG. 4.

As shown in FIG. 4, the wiring 212 for a cartridge 100 runs from the electrical connectors 206 in each recessed area 110 a-h into channels 232 a-b provided in cartridge 100 which run above each attachment area 130 a-b (a similar channel 732 a is also shown in FIG. 7). Each of the channels 232 a-b is connected to a transverse central channel 278 which runs through cartridge 100, which houses the common bus system 280. The wiring 212 connects electrical connectors 206, and thus the photovoltaic panel engaged in each recess 110 a-h to the common bus system 280. Although the common bus system 280 in each cartridge 100 can be terminated at an electric harvester on a cartridge 100 support structure, such as is shown in FIG. 12, FIG. 4 shows an embodiment where each cartridge 100 can be equipped with a male electrical connector 216 and female electrical connector 218 for interconnecting the common bus systems 280 of multiple cartridges 100, together. In this manner, as the cartridges 100 are slid into position on a support structure in the manner discussed in more detail below and pressed against each other, corresponding male 216 and female 218 connectors engage to electrically connect the photovoltaic panels of adjacent cartridges 100. Interconnected cartridges 100 can then transfer electric power to a common point and onward to an electrical inverter before connecting to an electrical grid.

As shown in FIGS. 1 and 5, each cartridge 100 has attachment structures 130 a-b in the form of grooves on the cartridge underside to seat the cartridges 100 on support structures. FIG. 6A shows an exemplary cartridge 100 with its attachment structures 130 a-b being slidably mounted on a support structure 600 comprising a set of spaced parallel rails 640 a-b. FIGS. 1, 5 and 6A show that for cartridge 100, the attachment structures 130 a-b are on the under side of the cartridge 100. FIG. 6B shows an alternate embodiment of a cartridge 600 where the attachment structures are provided in the form of slots 630 a-b on side edges of the cartridge 600, which are mounted on and engage with a support structure 601 that also comprises a set of spaced parallel rails 641 a-b.

As can be seen in FIGS. 6A, 6B, a cartridge 100, 600 can be slid onto the rails 640 a, 640 b or 641 a, 641 b (FIG. 6B) for mounting in the field. Successive cartridges 100, 600, each containing a plurality of photovoltaic panels (in this embodiment), can be advanced (by sliding) onto the rails one after another, resulting in considerably reduced field installation time. In addition, adjacent cartridges 100, 600 can be electrically connected to one another by mating male and female electrically connectors 216, 218.

As mentioned above, row length in large-scale PV systems can be half a mile or more. In order to easily slide cartridges along such a long path, as shown in FIG. 7, cartridge 700 may use a roller truck 760 mounted within the attachment structure 730 a, which facilitates easier sliding movement across long stretches of rail 740. FIG. 7 also shows a channel 732 a above attachment structure 730 a, for routing wiring 712 to an electrical connector 708 in a corresponding recessed area 710 a.

The truck 760 comprises a plurality of paired spaced rollers 764 a-b mounted on a corresponding axle 762. The truck 760 only takes up a small portion of space inside the attachment structure 760 a, so that a rail 740, which may have a T or other cross-sectional shape, can extend far enough in the attachment structures 730 a-b to stabilize the cartridge 700. Once a cartridge 700 is slid into position on the rails 740, it can be secured to the rails 740 by extending a set screw 752 (in channel 750) or other fastener to engage a groove 742 in the rail 740. Advantageously, the set screw 752 also functions as an electrical ground, if made of conductive material, grounding a conductive cartridge 700, to a conductive rail 740.

Although, as shown in FIG. 7, truck 760 may use multiple equally spaced rollers 764 a-b, a truck could also use any sliding movement assisting structure, including a single roller on an axle (such as the rollers 864 a-b in FIG. 8) or ball bearings (such as bearings 766 a-b in FIG. 9). Generally, the trucks 760 are manufactured separately from the cartridges 700 and are mounted in the attachment structures 730 a-b by screw, bolt, glue, or other fastener. However, the trucks 760 could also be integral to the attachment structures, and, as shown in the alternate embodiment of FIG. 8, rollers 864 a-b could be installed directly inside attachment structure 830 a. Referring back to FIGS. 1, 5 and 6A, the attachment structures 130 a-b or 630 a-b can take the form of simple grooves, and a non-stick, or low friction slidable surface such as a Teflon®-coated surface can be applied within the grooves instead of using a truck 760 to facilitate sliding movement of a cartridge.

FIG. 9 shows an alternate embodiment of a cartridge 900 having a truck 960 which comprises a plurality of paired spaced ball bearings 966 a-b, which are mounted in upper and lower housings 964 a-b and 968 a-b respectively. Truck 960 also has a pair of arms 962 a-b that extends to engage corresponding grooves 942 a-b in a support rail 940. Though only shown in this embodiment, it should be understood that any truck 760, 960 could use such arms 962 a-b which engage the corresponding grooves 942 a-b in the support rail. The FIG. 9 truck 960 is secured to attachment structure 930 a by means of screw 970 or other fastener, which is driven through a top surface of the attachment structure 930 a into the body of cartridge 900. Other trucks that may be employed are described in more detail in co-pending application Ser. No. 12/846,686, the entire disclosure of which is incorporated herein by reference. The trucks 760, 960 described herein and in application Ser. No. 12/846,686 can be used on any of the cartridges 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300 described herein.

FIGS. 10A-10C show an embodiment in which cartridge 1000 is constructed of a frame structure of spaced elongated members 1010 a-d. The spaced elongated members 1010 a-d are preferably formed in a U-shape with outwardly extending flanges on either top side. This shape is also known as a hat channel. Attachment structures 1030 a-b are fastened transversely across and beneath the spaced elongated members 1010 a-d for, as shown in FIG. 10A, slidably connecting the cartridge 1000 to support rails 1040 a-b. Photovoltaic panels, e.g., 1020 a-b, are mounted on top of the spaced elongated members 1010 a-d and secured by clips 1012 a-b or other fastener to the elongated members 1010 a-d. As with the FIG. 1-5 embodiment, glue, Velcro™, or other known engagement means can be used to secure the photovoltaic panels 1020 a-d to the spaced elongated members 1010 a-d. An optional exterior rim 1050, shown in dotted lines in FIG. 10A, is fit around the outside of the cartridge and fastened to the ends of both the spaced elongated members 1010 a-d and attachment structures 1030 a-b. The optional exterior rim 1050 provides added structural support and also enables the cartridge 1000 to be stacked with other cartridges. Preferably, the spaced elongated members 1010 a-d, photovoltaic panels 1020 a-d, and attachment structures 1030 a-b are all arranged within the dimension of the thickness of exterior rim 1050 so they do not project beyond a top or bottom surface of the rim 1050 of the cartridge 1000, enabling stacking of cartridges 1000.

Cartridge 1000 is also equipped with a common bus system 1080. Wiring 1012 for the common bus system 1080 is run through the spaced elongated members 1010 a-d. FIG. 10A shows a series of plugs 1006, for connecting the photovoltaic panels 1020 a-d to the common bus system 280. The common bus system 1080, through a channel 1078 transversely mounted to the bottom of spaced elongated members 1010 a-d, also has a plug 1014 and plug 1016 on opposite sides of the exterior rim 1050 of the cartridge 1000 for electrically interconnecting adjacent cartridges 1000.

FIG. 10B shows a side view of cartridge 1000 along axis A of FIG. 10A, showing a photovoltaic panel 1020 a mounted on spaced elongated member 1010 a, along with attachment structure 1030 a and rail 1040 a. It should be understood that trucks, e.g., 760, 960 can be mounted in attachment structure 1030 a as well, and that attachment structure 1030 a may be fitted with holes or screw threads (not shown) that can be used with fasteners, e.g., screw 970 on truck 960 or fit with portions of the truck, e.g., 760, 960 to secure and stabilize the truck within the attachment structure 1030 aD. FIG. 10C shows a cross-section of cartridge 1000 along axis B of FIG. 10B, showing photovoltaic panel 1020 a mounted on spaced elongated members 1010 a-b along with exterior rim 1050.

FIGS. 11-13 show another embodiment of a cartridge 1100 that does not employ a truck. The cross sectional profile of the attachment structures 1130 a-b, which are formed as grooves in the underside of cartridge 1100, matches that of the rails 1140 a-b, which are generally T-shaped in cross-section. FIGS. 12 and 13 show this embodiment in more detail. Rails 840 a-b are mounted on a support table 1190 or other supporting structures, such that cartridge 1100 is suspended above the table by the rails 840 a-b. As can be seen in FIG. 11, the rails 1140 a-b are transversely mounted to flange 1152 on the table 1050. The rails 1140 a-b themselves are hollow and can be compressed, which allows sliding of the cartridges 1100 along the rails, and after the cartridges 1100 are slid into place, provide resistance which holds the cartridges 1100 to the rails 1140 a-b. FIG. 12 also shows that cartridge 1100 is connected to an electrical harness 1192 on a support table post support structure 1150 via plug 1118, so that collected photovoltaic-generated electricity can be gathered and sent to a power grid.

Although the rails depicted in FIGS. 6A-9 and 11-13 have a generally T-shaped profile, it should be understood that another cross-sectional rail profile, e.g., circular or I-shaped, could be used. Further, it should be understood that although the mounting system described herein (e.g., 601 shown in FIG. 6B) is generally used for ground mounted installations (as in FIG. 12).

A plurality of cartridges may be stacked together and shipped to an installation site. For this reason, the cartridges, e.g., 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300 are generally designed to lie flat or fit together vertically and are configured to protect the photovoltaic panels in transit, and the trucks, e.g., 760, 960 are designed to be completely contained flush or preferably entirely within the attachment structures. In addition, as noted above, the photovoltaic panels are preferably recessed in the cartridges 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, and 2300. Optionally, as is shown in FIG. 14, a cartridge 1400 can have one or more openings 1402 so that when cartridges are stacked, a threaded securing member (not shown) can be inserted in opening 1402 and topped with bolts to ensure the cartridges remain secure in place during transit. Cartridge 1400 may also have a plurality of protrusions 1404 a, 1404 b to engage corresponding recesses (not shown) in the backside of cartridge 1400 to help hold a stack of cartridges together as an integrated unit. Alternately, or in addition to the protrusions 1404 a, 1404 b, and associated recesses, the cartridge 1400 can be formed with a self-aligning lip 1450 that engages a corresponding recess (not shown) on the backside of cartridge 1400 for the same purpose.

FIG. 15 shows a cartridge 1500 according to another embodiment from a top view. In this embodiment, the cartridge 1500 may be manufactured from a frame 1505, central beam 1524, and a pair of struts 1522 a,b. The cartridge 1500 is then loaded with an array of eight photovoltaic panels 1510 in a two column-four row array as shown. The cartridge 1500 is mounted and installed on parallel cartridge mounting rails 1540 a. The cartridge mounting rails 1540 a may be provided on a ground or roof support structure as is shown and described below.

FIGS. 16A, B, and D show the frame 1505, central beam 1524, and struts 1522 a,b (only 1522 a is shown in FIG. 16B) in more detail. FIG. 16A shows a cross-section of the frame 1505 along line 16A-16A of FIG. 15. FIG. 16B shows a cross-section of the strut 1522 a along line 16B-16B of FIG. 15. FIG. 16D shows a cross section of the central beam 1524 along line 16D-16D of FIG. 15. Each of the frame 1505, central beam 1524, and strut 1522 a are formed from a rolled metal, such as galvanized steel. As is shown in FIGS. 16A, B, and D, a reinforced area 1536 a-f of folded over metal is provided along the entire length of the frame 1505, central beam 1524, and strut 1522 a at the top and bottom parts to provide increased stability and torsion resistance. The frame 1505 and central beam 1524 are provided mounting regions 1537 a,b to facilitate installation of photovoltaic panels as described below. Similarly, the strut 1522 a is provided a mounting channel 1533. The frame 1505 and central beam 1524 also have fixation holes 1534 to permit installation of a bracket (shown in FIG. 20A-C) to secure the photovoltaic panels within the mounting regions 1537 a,b as described below. In one embodiment, shown in FIG. 16A, the frame 1505 is formed to create a nesting channel 1539 to allow one cartridge 1500 to be stacked upon another cartridge, as shown below in FIG. 21A-C. As is shown in FIGS. 16A, B, and D, the frame 1505 is taller than the central beam 1524 and struts 1522 a,b to allow one cartridge to stack upon another cartridge but prevent the central beam 1524 and struts 1522 a,b from contacting with and damaging the photovoltaic panels 1510 of the next lowest cartridge when cartridges are stacked.

As is shown in FIG. 16B, the strut 1522 a is formed with opposed arms 1538, to allow the strut to wrap around a T-shaped cartridge mounting rail 1540 a to prevent the cartridge 1500 from lifting off of the cartridge mounting rails 1540 a, while also permitting the cartridge 1500 to slide along the rails 1540 a. In another embodiment, shown in FIG. 16C, the strut 1522 c and opposed arms 1538 a are formed with a generally U-shaped cross section, which permits the strut 1522 c to be attached to a T-shaped or other shaped cartridge mounting rail in either a downward direction from above the rail or slid onto the rail from the rail end. Once attached to the mounting rail the cartridge utilizing the strut 1522 c could be slid to a mounting location along the rails

A wheel assembly 1541 formed of a wheel 1542 and axle 1543 can be provided which allows the cartridge 1500 to slide easily along the cartridge mounting rails 1540 a of FIG. 15. It can be appreciated that other means may be used to facilitate the sliding of the cartridge 1500 to slide along the cartridge mounting rails 1540 a, such as ball bearings or low friction surfaces, as described in U.S. patent application Ser. No. 12/846,686, and described above and shown in FIGS. 8 and 9. The strut 1522 a also has a fastener hole 1552 to allow a fastener to be inserted through the strut 1522 a and engage the strut 1522 a with the cartridge mounting rail (shown in FIG. 15) to allow the cartridge 1500 to be fixed in place once the cartridge 1500 has reached a desired mounting location.

In another embodiment, shown in FIGS. 16E-G, the mounting channels 1533 a,b are provided on the central beam 1524 a and frame 1505 a. The mounting regions 1537 c are provided on the strut 1522 d. Similar to FIG. 16C, the strut 1522 d has a generally U-shaped cross-section, allowing it to be attached to a cartridge mounting rail from above the rail or to be attached by sliding the cartridge onto the rail from the rail end.

FIGS. 17A-D show the installation of a photovoltaic panel 1510 into a cartridge strut 1522 a and frame element 1505 from the side perspective. In the embodiment shown, the photovoltaic panel 1510 is installed with the top surface of the cartridge 1500 facing down. In another embodiment, the photovoltaic panel may be installed from below with the cartridge 1500 facing up. The mounting regions 1537 a of frame 1505 and mounting channel 1533 of strut 1522 a are configured to hold a photovoltaic panel 1510. The photovoltaic panel 1510 may be provided with molded cushion pads 1511 to protect the photovoltaic panel 1510 edges from being damaged when installed into the cartridge 1500. The photovoltaic panel 1510 is inserted into the C-shaped mounting channel 1533 at an angle θ, which may be in a range of 30° to 60°. In order to facilitate the installation of the photovoltaic panel 1510 into the mounting channel 1533 and allow the panel 1510 to tilt to the proper angle, the arms 1538 of the strut 1522 a may be provided an angled portion 1535 at the mounting channel 1533.

Next, as shown in FIG. 17B, once one edge of the photovoltaic panel 1510 is inserted into the C-shaped mounting channel 1533 and the photovoltaic panel is lowered into position so that the opposite edge is seated into a corresponding mounting region 1537 a on the frame 1505, a bracket 1546 is provided to fasten the photovoltaic panel in place as is shown in FIGS. 17B-C. A fastener 1545 is provided to be inserted through a fastener hole 1547 in the bracket 1546, and into the fixation hole 1534 of the frame 1505. In one embodiment, the fixation hole 1534 and/or the fastener hole 1547 are threaded to engage a threaded fastener. In another embodiment, the fixation hole 1534 and/or the fastener hole 1547 are smooth and the fastener is a bolt and nut. FIG. 17C shows the bracket 1546 being fastened to the frame element 1505 to secure the photovoltaic panel 1510 in place. The bracket 1546 may be fastened to the frame element by use of rivets, welds, or other similar fastener means or attachment structures. A second and third photovoltaic panel 1510 may also be similarly installed between the central beam 1524 and the struts 1522 a,b and shown in FIGS. 15 and 17D. Brackets 1546 a,b fasten the photovoltaic panels 1510 to the central beam 1524. A fastener 1545 is passed through the two brackets 1546 a,b and the central beam 1524 to secure the photovoltaic panels 1510 in place.

As shown in FIG. 17E in another embodiment, the frame 1505 a, central beam 1524 a, and strut 1522 c of FIGS. 16D-F may be used in place of the frame 1505, central beam 1524, and strut 1522 a, shown in FIGS. 17A-D, to create a cartridge 1500 a having a U-shaped channel on the struts 1522 d. In this embodiment, the installation of the photovoltaic panels would proceed similarly to that shown in FIGS. 17A-C. One side of the photovoltaic panels 1510 is inserted at an angle into a mounting channel 1533 a,b of either the central beam 1524 a or frame 1505 a. The opposing side of the photovoltaic panel 1510 is then lowered onto the mounting regions 1537 c of the strut 1522 d. Finally, brackets 1534 are affixed to the strut 1522 d to secure the photovoltaic panels 1510 in place.

FIG. 18 shows a fully-loaded cartridge 1500 from below. The cartridge 1500 has eight mounted photovoltaic panels 1510, installed as described above. Six wheels assemblies 1541 are provided and spaced at locations along struts 1522 a,b, however, more or fewer wheel assemblies 1541 may be utilized as desired and required to support the cartridge 1500.

In one embodiment, shown in FIGS. 19A-F, the frame 1505 may be formed from one continuous piece. As is shown from the top in FIG. 19A and side in FIG. 19B, a frame blank 1504 is provided and pre-notched at the locations 1507 where the cartridge 1500 will be mounted on the cartridge mounting rails 1540 a. The frame blank 1504 has four sections A, B, C, and D, each correspond to one side of the completed frame 1505. In one embodiment, the four sections (A, B, C, and D) are of equal length. In another embodiment, a given section (e.g. A) is equal in length with its opposing sections (i.e. C), but is of a different length from adjacent sections (i.e. B and D). The frame blank 1504 is then bent as shown in FIG. 19C-E at locations 1506 between the sections A, B, C, and D to form the completed frame 1505. The frame blank 1504 is notched at locations 1508 in the reinforced areas 1536 a,b at the locations 1506 to allow the frame blank 1504 to be bent into the configuration shown in FIGS. 19E and 19F. Once the bends have been made, the notched reinforced areas 1536 a,b may be welded together or otherwise fastened together to increase the strength of the frame 1505. The ends of the completed frame 1505 are joined together by fasteners, welding, or other fastening techniques.

Once the frame 1505 is assembled, as shown in FIGS. 19E and 19F, the central beam 1524 and the struts 1522 a,b are fastened in place as shown in FIG. 20. The struts 1522 a,b are attached to align with the notches in the frame 1505, with the central beam 1524 centered between the struts 1522 a,b. The struts 1522 a,b and central beam 1524 are provided with flanges 1527, 1529 by which the struts 1522 a,b and central beam 1524 are fastened to the frame 1505. The struts 1522 a,b and central beam 1524 may be fastened to frame 1505 using flanges 1527, 1529 with bolts, screws, rivets, welds, or other similar attachment techniques.

FIG. 21A shows a stack 1508 of completed cartridges 1500, which FIG. 21B shows in more detail. As is shown in FIG. 21B, a cross-section of 21A with one side of the frame 1505 removed, the frames 1505 are configured to nest with one another. As was discussed above with respect to FIG. 16A, the lower reinforced area 1536 b of a cartridge 1500 rests upon the nesting channel 1539 of the cartridge 1500 below it. Because this reinforced area 1536 b and nesting channel 1539 follow the perimeter of the cartridge 1500, the cartridges 1500 nest into one another to prevent the cartridges 1500 from sliding and becoming damaged. This allows multiple cartridges 1500 to be transported together more easily and compactly as shown in FIG. 21C, while protecting the edges of the photovoltaic panels 1510 and eliminating the necessity of using dunnage and pallets in transporting the cartridge stacks 1508.

Once the cartridges of the various embodiments discussed above (e.g. 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300) have been transported to the installation site and are prepared for installation on the corresponding support structure, the cartridges 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300 may be installed in one of several manners. These installation methods, described below, may be used with cartridges 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300 of any of the embodiments discussed above but are described in detail in the following exemplary embodiments.

As discussed above, the cartridges 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300 may be installed by manually placing the cartridges 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300 one after another onto the rails (e.g. 640 a,b), (for example, by lowering the cartridge 100 onto the rails 640 a,b or aligning attachment structures (e.g. 130 a,b, 1130 a,b, 1522 a,b,c,d) on the cartridges to the rails) and advancing them by having an operator slide them on the rails 640 a,b into a desired position. This placing and sliding can be done at the head end of a row or at spaced positions along a row. Head-end installation reduces equipment and labor movement. Both the rails 640 a,b and the cartridges 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300 are designed so that cartridges can quickly be placed onto rails and slid into a final position.

The cartridges (e.g. 2200, 2200 b) may be deployed manually as shown in FIGS. 22A-D. FIG. 22A shows a first cartridge 2200 being lowered onto support structure 2240 via a lifting device 2210. Lifting device 2210, which is attached to an overhead cable 2211, can comprise (as shown) an adjustable frame 2212 that holds a cartridge (e.g., 2200) by its edges. Each side of the frame 2212 can be opened or closed by engaging a corresponding latch 2213 a, 2213 b. FIG. 22B shows cartridge 2200 securely placed on the support structure 2240, after which it can be slid down the structure, as shown in FIG. 24C. FIG. 22D shows the placement and subsequent positioning of a second cartridge 2200 b after the first cartridge 2200.

FIG. 23 shows another embodiment of a cartridge 2300 for holding a single photovoltaic panel 121 and having a pair of attachment structures 130 a-b. Similar to the cartridge of FIG. 1 which holds multiple panels, cartridge 2300 can be optionally connected to other cartridges 2300 using a male electrical connector 216 (not shown) and female electrical connector 218 on an outer part of a frame of the cartridge 2300. It should be understood that the various methods and structures described herein for mounting photovoltaic panels on a multi-panel cartridge, e.g., 100, are applicable to single panel cartridges, e.g., 2300, as well. For instance, similar to cartridge 100, cartridge 2300 can have a recessed area (110 in FIG. 1) and an engagement mechanism for holding photovoltaic panel 121 within the recessed area, and an electrical connector (206 in FIG. 2) located within the recessed area for electrically connecting the photovoltaic panel 121 to connectors 216, 218.

Similar to FIG. 6A, as shown in FIG. 24A, a first single-panel cartridge 2300 can be placed on the parallel spaced rails 2440 a-b of support structure 2400 and slid down the rails far enough to place another cartridge on the rails 2440 a-b in place behind it, so it too can be slid down the rails 2440 a-b. It should be understood that cartridge 2300 could be placed on the rails 2440 a-b by simple lifting, or a winch could be used. Alternatively, cartridge 2300 could be lined up over the rails 2440 a-b and lowered on top of them. It should also be appreciated that the same methods of mounting the cartridges described in other embodiments, e.g., for cartridge 100, can be used. Further, since it may be difficult to manually push successive cartridges, e.g., 100, 2300 over long distances, cartridges could be lowered onto a rail e.g., 640 a-b, 2440 a-b at set locations spaced along the rail and then slid into position. Alternatively, a robotic system as described in application Ser. No. 12/846,644 can be used to place the cartridge 2300 on rails 2440 a-b and slide them down the rails.

FIG. 24B shows a second cartridge 2300 b being placed on parallel spaced rails 2440 a-b of the support structure 2400 behind the first cartridge 2300. The cartridges 2300, 2300 b are pressed together, so as to facilitate movement in tandem along the support structure. As mentioned above, this connection may also facilitate electrically interconnecting the photovoltaic panels on the cartridges 2300, 2300 b via connectors 216, 218. Cartridges 2300, 2300 b can also be held together by any suitable fastening means 2310 (shown in FIG. 23), such as complementary locking or latching structures, or Velcro™, or any other fastening mechanism, mounted on the outside of the cartridges 2300, 2300 b. Once contacted, cartridges 2300, 2300 b can be slid in tandem along the support structure. As subsequent cartridges 2300 are placed on the rails, the installer can advance the already mounted cartridges 2300 incrementally further down an array row. The installation process continues until a desired number of cartridges have been placed on the rail and slid into position.

It should be noted that the support structure 2300 is shown as being designed to run along a horizontal surface of a roof, as opposed to perpendicular to it (i.e. in a vertical direction). Although the support structures (e.g., 2400) described herein could be adapted to vertical mounting, horizontal mounting is preferred because it permits cartridges to be slid into a desired position without requiring a locking mechanism to prevent the cartridges from falling back down the structure. It should also be understood that various combinations of trucks or no trucks, and different types of rails can be used with any of the cartridges (e.g., 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300) described herein.

Since, as noted above, manual installation of cartridges can become difficult as the row length increases, a more automated cartridge mounting and delivery system may be used. One such delivery system is described in more detail in co-pending application Ser. No. 12/846,644, which is incorporated by reference herein.

FIG. 25 shows such a robotic installation system 400 for deployment of cartridges. For simplification, only cartridges 100 are shown in FIG. 25, but it should be understood that the illustrated installation system 400 may be used with any of cartridges 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200 and 2300. During operation, the robot arm 410, to which the frame 460 of a vacuum system 430 is attached, moves to align the frame 460 over a first exemplary FIG. 1 cartridge 100, situated as the top cartridge 100 in a magazine 500 comprising a plurality of cartridges 100 stacked together. Once aligned, the vacuum is activated and suction cups 470 are engaged with the photovoltaic panels 120 a-h of the cartridge 100. The robot arm 410 the lifts the cartridge 100 off the magazine 500 and moves the cartridge 100 over to the rail system 340 a-b.

As seen in FIGS. 26A-E, once first exemplary cartridge 100 is placed on the rails 340 a-b at location 2650 (shown here as an end of the row location), a push actuator 480 pushes a first cartridge 100 down the rails 340 a-b. As best seen in FIG. 26A, the push actuator 480 has a flat surface 485 to engage the edge of the cartridge 100. A telescoping arm 490 extends to press the cartridge 100 down the rails 340 a-b (FIGS. 26B-D). As seen in FIG. 26E, once the first cartridge 100 is in place, a second cartridge 100 b can be lowered onto the rails 340 a-b and pushed by the push actuator 480 along the rails 340 a-b. The first and second cartridges 100, 100 b can also be pushed together along the rails 340 a-b. In this manner, multiple cartridges 100 can be pushed simultaneously, in order to install a plurality of cartridges 100 onto the rail system 340 a-b from an end of the row location 2650.

In another embodiment, shown in FIGS. 27A and 27B, the cartridge 1500 of FIG. 15 may be mounted onto the T-shaped cartridge mounting rails 1540 a from the end of the cartridge mounting rails 1540 a as shown, similar to as described above with respect to FIGS. 24A and 24B. Once the cartridge 1500 is slid onto the end of the cartridge mounting rails 1540 a, a push actuator 480 pushes the cartridge 1500 along the rails as shown in FIG. 24B.

In another embodiment, the cartridge rails may be configured without the T-shape at an installation location along the cartridge mounting rails 1540 b as is shown in FIG. 27C. At this location along the rails, the cartridge 1500 may be lowered onto the rails as described above. Then, the push actuator 480 would slide the cartridge 1500 onto the T-shaped rails, and, from then, moved to its mounting location along the cartridge mounting rails 1540 b. In another embodiment, shown in FIG. 27D, the cartridge 1500 a, shown in FIG. 17E, could be installed onto the cartridge mounting rails 1540 c either vertically or horizontally as discussed above. Similar to the embodiments described above, a push actuator 480 may then move the cartridge 1500 a.

FIG. 28A shows a side view of the cartridge 1500 of FIG. 15 mounted to the cartridge mounting rails 1540 a. As can be seen, the arms 1538 of the struts 1522 a,b wrap underneath T-shaped cartridge mounting rails 1540 a, while the wheel assembly 1541 allows the cartridge 1500 to roll along the cartridge mounting rails 1540 a. When the cartridge 1500 reaches its mounting location, fasteners 1552, such as pins or bolts, may be inserted through mounting holes 1553 in the struts 1522 a,b and into the cartridge mounting rails 1540 a to secure the cartridge 1500 at its mounting location along the cartridge mounting rails 1540 a.

As shown in a second embodiment in FIG. 28B, a cartridge 1500 b that utilizes struts 1522 c,d of the kind shown in FIG. 16C may be installed onto the T-shaped cartridge mounting rails 1540 a in a vertical direction, similar to as shown in FIGS. 22A-D. The cartridge 1500 b may then roll along cartridge mounting rails 1540 a to its mounting location. This configuration of cartridge 1500 a has the advantage of being able to be lowered onto the cartridge mounting rails 1540 a without having to be inserted onto the rails from the end. Similarly to the embodiment shown in FIG. 27A, once the cartridge 1500 a reaches its mounting location, fasteners 1552, such as pins or bolts, are inserted through mounting holes 1553 in the struts 1522 c and into the cartridge mounting rails 1540 a.

In a third embodiment, shown in FIG. 28C, a cartridge 1500 a is configured to be installed on rectangular cross-section cartridge mounting rails 1540 c. This cartridge 1500 a may be installed either from the end, as described and shown with respect to cartridge 1500, or vertically as described and shown with respect to cartridge 1500 b of FIG. 28B. The cartridge 1500 a is then rolled to its mounting location, at which point fasteners 1552, such as pins or bolts are inserted through mounting holes 1553 in the struts 1522 d and into the cartridge mounting rails 1540 c.

Deployment of cartridges at spaced positions along a row or at the end of each row reduces equipment and labor movement. Both rails and cartridges are designed so the cartridges can quickly be placed onto the rails and slid along the rows and moved into a final position. In this manner, each cartridge mounts one or more photovoltaic panels (e.g., one, four or eight, as shown in the Figs.) at once to a set of rails, thereby simplifying installation time and cost. A field installation 2000 is shown in FIGS. 29A and 29B. In such an installation, a plurality of rows of rails (e.g., 640 a-b, 2340 a-b) are set up, onto which cartridges (e.g., 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300) can be installed in sequence, a row at a time, from spaced positions along each row. Optionally, a robotic installation system 400 can be used.

It should also be noted that the cartridges (e.g., 100, 600, 700, 800, 900, 1000, 1100, 1400, 1500, 2200, and 2300) can be prewired to facilitate photovoltaic panel interconnection and the cartridges themselves can plug into one another to further reduce installation labor. It should also be noted that any other system components, such as wire harnesses, DC/DC converters, and the like could also be slid in from the ends of the rows, to further increase installation efficiency.

While embodiments have been described in detail, it should be readily understood that the invention is not limited to the disclosed embodiments. Rather the embodiments can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described. Although certain features have been described with some embodiments of the cartridge, such features can be employed in other disclosed embodiments of the cartridge as well. Accordingly, the invention is not limited by the foregoing embodiments, but is only limited by the scope of the appended claims. 

1. A cartridge for mounting a plurality of photovoltaic panels thereon comprising: a frame; at least a first strut transversely mounted to a first side of the frame and a second side of the frame, opposite the first side, wherein a first mounting channel is provided on one of the frame and the first strut, and a first mounting region is provided on the other of the frame and the first strut.
 2. The cartridge according to claim 1, further comprising a central beam transversely mounted to the first side of the frame and the second side of the frame, wherein the central beam is mounted such that the first strut is provided between the central beam and a third side of the frame, wherein a second mounting channel is provided on one of the central beam and the first strut, and a second mounting region is provided on the other of the central beam and first strut.
 3. The cartridge according to claim 2, further comprising a second strut transversely mounted to the first side of the frame and the second side of the frame, wherein the second strut is mounted such that the second strut is provided between the central beam and a fourth side of the frame, wherein a third mounting channel is provided on one of the central beam and the second strut and a third mounting region is provided on the other of the central beam and the second strut, and wherein a fourth mounting channel is provided on one of the frame and the second strut and a fourth mounting region is provided on the other of the frame and the second strut.
 4. The cartridge according to claim 1, wherein the frame is formed from one continuous frame blank.
 5. The cartridge according to claim 1, wherein the frame comprises: a first side; a second side, opposite the first side, wherein the first side and the second side are of equal lengths; a third side; a fourth side opposite the third side, wherein the third side and fourth side are of equal lengths.
 6. The cartridge according to claim 5, wherein the first side, second side, third side, and fourth side are of equal lengths.
 7. The cartridge according to claim 1, wherein the frame comprises a longitudinal extent and a reinforced area, wherein the reinforced area is provided along the longitudinal extent.
 8. The cartridge according to claim 1, wherein the first strut comprises a longitudinal extent and a reinforced area, wherein the reinforced area is provided along the longitudinal extent.
 9. The cartridge according to claim 2, wherein the central beam comprises a longitudinal extent and a reinforced area, wherein the reinforced area is provided along the longitudinal extent.
 10. The cartridge according to claim 2, wherein a top surface of at least one of the frame, first strut, and central beam comprise a reinforced area.
 11. The cartridge according to claim 3, wherein the first strut and the second strut are configured to attach to corresponding cartridge mounting rails associated with a support structure.
 12. The cartridge according to claim 11, wherein the frame has first and second notches corresponding to a first location and a second location where the first strut is mounted to the frame and third and fourth notches corresponding to a third location and a fourth location where the second strut is mounted to the frame, wherein the notches are configured to allow the frame to move over the cartridge mounting rails.
 13. The cartridge according to claim 1, further comprising a first photovoltaic panel mounted to the cartridge, wherein a first longitudinal side of the first photovoltaic panel is inserted into the mounting channel and a second longitudinal side of the first photovoltaic panel, opposite the first longitudinal side, rests in the mounting region.
 14. The cartridge according to claim 3, further comprising: a first photovoltaic panel mounted to the cartridge, wherein a first longitudinal side of the first photovoltaic panel is inserted into the mounting channel and a second longitudinal side of the first photovoltaic panel, opposite the first longitudinal side, rests in the mounting region; a second photovoltaic panel mounted to the cartridge, wherein a third longitudinal side of the second photovoltaic panel is inserted into the second mounting channel and a fourth longitudinal side of the second photovoltaic panel, opposite the third longitudinal side, rests in the second mounting region; a third photovoltaic panel mounted to the cartridge, wherein a fifth longitudinal side of the third photovoltaic panel is inserted into the third mounting channel and a sixth longitudinal side of the third photovoltaic panel, opposite the fifth longitudinal side, rests in the third mounting region; and a fourth photovoltaic panel mounted to the cartridge, wherein a seventh longitudinal side of the fourth photovoltaic panel is inserted into the fourth mounting channel and a eighth longitudinal side of the fourth photovoltaic panel, opposite the seventh longitudinal side, rests in the fourth mounting region.
 15. The cartridge according to claim 3, further comprising eight photovoltaic panels mounted therein.
 16. The cartridge according to claim 15, wherein: a first longitudinal side of the first photovoltaic panel and a first longitudinal side of the second photovoltaic panel are inserted into the first mounting channel and a second longitudinal side of the first photovoltaic panel and a second longitudinal side of the second photovoltaic panel opposite their respective first longitudinal sides are secured in the first mounting region; a first longitudinal side of the third photovoltaic panel and a first longitudinal side of the fourth photovoltaic panel are inserted into the second mounting channel and a second longitudinal side of the third photovoltaic panel and a second longitudinal side of the fourth photovoltaic panel opposite their respective first longitudinal sides are secured in the second mounting region; a first longitudinal side of the fifth photovoltaic panel and a first longitudinal side of the sixth photovoltaic panel are inserted into the third mounting channel and a second longitudinal side of the fifth photovoltaic panel and a second longitudinal side of the sixth photovoltaic panel opposite their respective first longitudinal sides are secured in the third mounting region; and a first longitudinal side of the seventh photovoltaic panel and a first longitudinal side of the eighth photovoltaic panel are inserted into the fourth mounting channel and a second longitudinal side of the seventh photovoltaic panel and a second longitudinal side of the eighth photovoltaic panel opposite their respective first longitudinal sides are secured in the fourth mounting region.
 17. The cartridge according to claim 3, wherein: the first mounting region and the fourth mounting region are provided on the frame; the first mounting channel and the second mounting channel are provided on the first strut; the second mounting region and the third mounting region are provided on the central beam; and the third mounting channel and the fourth mounting channel are provided on the second strut.
 18. The cartridge according to claim 3, wherein: the first mounting channel and the fourth mounting channel are provided on the frame; the first mounting region and the second mounting region are provided on the first strut; the second mounting channel and the third mounting channel are provided on the central beam; and the third mounting region and the fourth mounting region are provided on the second strut.
 19. The cartridge according to claim 11, wherein each strut is configured to move along its corresponding cartridge mounting rail.
 20. The cartridge according to claim 19, wherein each strut comprises a plurality of wheel assemblies configured to allow the cartridge to move along the cartridge mounting rails.
 21. The cartridge according to claim 13, further comprising at least one bracket for securing the first photovoltaic panel to the cartridge, wherein the at least one bracket is fastened adjacent the mounting region.
 22. The cartridge according to claim 21, wherein the at least one bracket is fastened adjacent the mounting region using at least one of screws, bolts, rivets, and welds.
 23. The cartridge according to claim 1, wherein the frame is provided a nesting channel, wherein the nesting channel is configured to allow a frame of a second cartridge to seat within the nesting channel to allow the cartridge to be stackable.
 24. The cartridge according to claim 3, wherein the central beam and struts are fastened to the frame by at least one of screws, bolts, rivets, and welds.
 25. The cartridge according to claim 1, wherein the first strut comprises a first opposed arm and a second opposed arm, wherein the first opposed arm is configured to face a first side of a mounting rail and the second opposed arm is configured to face a second side of the mounting rail opposite the first side.
 26. The cartridge according to claim 1, wherein the first strut comprises a pair of opposed arms that are configured to wrap around a T-shaped cartridge mounting rail.
 27. The cartridge according to claim 25, wherein the first strut is provided the mounting channel, and further wherein an angled portion of the first opposed arm defines a first side of the first mounting channel and is configured to allow a photovoltaic panel to be inserted into the first mounting channel at an angle.
 28. The cartridge according to claim 1, wherein the first strut is provided the first mounting channel and a second mounting channel, wherein the first mounting channel is configured to receive the first side of the photovoltaic panel and the second mounting channel is configured to receive a first side of a second photovoltaic panel.
 29. The cartridge according to claim 1, wherein the frame comprises a first height and the first strut comprises a second height less than the first height.
 30. A method of constructing a cartridge for mounting a plurality of photovoltaic panels comprising: providing a rectangular frame comprising: a first side; a second side, opposite the first side, wherein the first side and the second side are of equal lengths; a third side; a fourth side opposite the third side, wherein the third side and fourth side are of equal lengths; transversely attaching at least a first strut to the frame, wherein the first strut is mounted to the first side of the frame and the second side of the frame; providing a first mounting channel on one of the third side of the frame and the first strut; providing a first mounting region on the other of the third side of the frame and the first strut, wherein a photovoltaic panel is mountable to the cartridge by inserting a first longitudinal side of the photovoltaic panel into the first mounting channel and securing a second longitudinal side of the photovoltaic panel to the first mounting region.
 31. The method of claim 30, further comprising: providing a frame blank; and bending the frame blank to form the rectangular frame.
 32. The method of claim 30, further comprising transversely attaching a second strut to the first side and the second side of the frame.
 33. The method of claim 32, further comprising transversely attaching a central beam to the frame, wherein the central beam is positioned between the first and second struts
 34. The method according to claim 30, further comprising inserting a photovoltaic panel into the first mounting channel.
 35. The method according to claim 34, wherein the photovoltaic panel is inserted into the first mounting channel at an angle of between approximately 30° and approximately 60°.
 36. The method according to claim 34, further comprising seating the photovoltaic panel into the first mounting region.
 37. The method according to claim 33, further comprising inserting a first side of a photovoltaic panel into a second mounting channel provided on one of the central beam and the first strut.
 38. The method according to claim 37, further comprising seating a second side of the photovoltaic panel opposite the first side into a second mounting region provided on the other of the central beam and the first strut.
 39. The method according to claim 36, further comprising fastening at least one bracket adjacent to the first mounting region in order to secure the photovoltaic panel to the cartridge.
 40. The method according to claim 30, wherein the first strut is attached to the frame by at least one of screws, bolts, rivets, and welds.
 41. The method according to claim 33, wherein the central beam is attached to the frame by at least one of screws, bolts, rivets, and welds.
 42. The method according to claim 30, further comprising notching the frame blank to allow the cartridge to travel along at least one cartridge mounting rail.
 43. The method according to claim 42, wherein the first strut is attached in alignment with the notches.
 44. The method according to claim 31, further comprising forming bend notches in the frame blank to allow the frame blank to be bent to form the frame.
 45. The method according to claim 44, further comprising welding a first end of the frame blank to a second end of the frame blank to form the rectangular frame.
 46. A method of installing a cartridge for mounting photovoltaic panels onto a support structure comprising: providing a cartridge comprising: a frame comprising: a first side; a second side, opposite the first side, wherein the first side and the second side are of equal lengths; a third side; a fourth side opposite the third side, wherein the third side and fourth side are of equal lengths. a first strut and second strut transversely mounted to the first side and the second side of the frame; wherein a photovoltaic panel is mountable to the cartridge by inserting a first side of the photovoltaic panel into a first mounting channel provided on one of the first strut and the frame and securing a second side of the photovoltaic panel to a first mounting region provided on the other of the frame and the first strut; affixing said first strut to a first cartridge mounting rail; affixing said second strut to a second cartridge mounting rail; sliding said cartridge to a mounting location along said cartridge mounting rails.
 47. The method according to claim 46, wherein said affixing step is accomplished by lowering said cartridge onto said cartridge mounting rail in a vertical direction.
 48. The method according to claim 46, wherein said affixing step is accomplished by sliding said cartridge onto said cartridge mounting rail in a horizontal direction.
 49. The method according to claim 46, further comprising inserting a fastener through said first strut and into said first cartridge mounting rail to secure the cartridge at the mounting location.
 50. The method according to claim 46, wherein said cartridge mounting rails have a T-shaped cross section.
 51. The method according to claim 46, wherein said cartridge mounting rails have a rectangular cross section.
 52. The method according to claim 50, wherein the struts comprise opposed arms that are configured to wrap around the top of the T-shaped cartridge mounting rails.
 53. The method according to claim 50, wherein the struts comprise opposed arms that define a generally U-shaped cross section.
 54. The method according to claim 50, wherein the struts comprise a plurality of wheel assemblies that permit the cartridge to roll along the cartridge mounting rails.
 55. A system for transporting a plurality of cartridges for mounting photovoltaic panels comprising: a first cartridge comprising: a first frame comprising: a first side; a second side, opposite the first side, wherein the first side and the second side are of equal lengths; a third side; a fourth side opposite the third side, wherein the third side and fourth side are of equal lengths; a nesting channel formed along the first, second, third, and fourth sides of the frame; a first strut transversely mounted to the first side and the second side of the frame; wherein a first mounting channel is provided on one of the first strut and the first frame, and a first mounting region is provided on the other of the first frame and the first strut; and a second cartridge comprising: a second frame comprising: a fifth side; a sixth side, opposite the fifth side, wherein the fifth side and the sixth side are of equal lengths; a seventh side; a eighth side opposite the seventh side, wherein the seventh side and eighth side are of equal lengths. a second strut transversely mounted to the fifth side and the sixth side of the frame; wherein a second mounting channel is provided on one of the second strut and the second frame, and a second mounting region is provided on the other of the second frame and the second strut; wherein the second frame is configured to seat onto the nesting channel of the first frame to facilitate stacking of the first and second cartridges.
 56. The system of claim 55, wherein the fifth, sixth, seventh, and eighth sides of the second frame comprise longitudinal extents with a reinforced area provided along the longitudinal extents of each of the sides.
 57. The system of claim 56, wherein the reinforced area is provided along a bottom portion of the fifth, sixth, seventh, and eighth sides of the second frame and is configured to seat onto the nesting channel of the first frame. 